Question

norovirus is most commonly caused by:
improper cleaning of surfaces
improper handwashing
not changing gloves between tasks
employees working while ill

Explanation:

Norovirus is highly contagious. Improper handwashing is a major cause as it allows the virus to spread easily from contaminated hands to the mouth. While the other options can contribute to the spread of norovirus, improper handwashing is the most common cause.

Answer:

Improper handwashing